HVACopediaNTI · Boiler
Lockout 82 Stack limit
What the control is telling you
Flue gas temperature at the stack sensor exceeded the stack limit.
Applies to: Trinity Tft60, Tft85, Tft110, Tft154, Tft201, Tft285, Tft340, Tft399
Likely causes
- Dirty heat exchanger or combustion chamber
- Stack limit setpoint wrong
- Faulty stack sensor
Test and repair steps
- Inspect and clean the combustion chamber and heat exchanger
- Set the stack limit setpoint to the maximum of 220 F (104 C); for PVC exhaust venting in Canada the limit is 149 F (65 C)
- Measure the sensor resistance and compare to the thermistor chart
Models that show this code
13 models in Trinity Tft
Other codes on the same units
- Lockout 60 Internal fault: HFS shorted to LFS
- Lockout 60 Internal fault: HFS shorted to LFS
- Lockout 71 Input power frequency mismatch
- Lockout 82 Stack limit
- Lockout 97 Internal fault: A2D mismatch
- Lockout 97 Internal fault: A2D mismatch
- Lockout 98 Internal fault: Exceeded VSNSR voltage tolerance
- Lockout 98 Internal fault: Exceeded VSNSR voltage tolerance
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Source: NTI Trinity Tft399 Installation and Operation Manual (2018-09-07), Sec. 16.0 Troubleshooting, Table 16-3. Summarized in our own words; check the original manual for your model.
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For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.